基于偏振分像的制冷器件晶粒双面等光程共焦成像缺陷检测装置

针对待测晶粒大的情况，为解决晶粒双面检测时双面之间产生光程差导致的的成像清晰度问题，提出了一种基于偏振分光成像法的半导体制冷器件晶粒相邻双面同时成像缺陷检测的装置。利用偏振分光器与直角转像棱镜对采用偏振分束器与偏振相机的晶粒天面和侧面同时等光程共焦成像检测装置进行了光学设计，完成了晶粒相邻双面同时等光程偏振成像缺陷检测的实验验证。结果表明，该偏振分光成像检测技术可以实现晶粒相邻面的同时缺陷检测，并能很好地满足相邻面等光程成像缺陷检测的性能要求。当晶粒相邻面等光程共焦时，检测分辨率可达到110 lp/mm以上，而当晶粒相邻面离焦（准共焦）仅±0.20 mm时，分辨率则降至45 lp/mm以下。本检测装置具有双面成像清晰度好、成像光路共焦调整方便、检测装置结构简单可靠，以及提高的缺陷检测性能等优点。

An apparatus for inspecting adjacent surfaces defects of TEC component based on equal-optical-path polarization splitting imaging

An apparatus for simultaneously inspecting adjacent surfaces defects of thermoelectric cooler (TEC) components based on polarization beam splitting imaging is proposed. The optical design of the apparatus for simultaneously inspecting adjacent surface defects of TEC components is discussed. The proposed apparatus employs polarization beam splitter and polarization camera and meets the conditions of equal-optical-path imaging for both top and side surfaces. The experimental investigations on defects inspection with equal-optical-path polarization imaging system are conducted. The results indicate that the proposed inspection technique with polarization splitting equal-optical-path imaging is capable of simultaneously inspecting the adjacent surfaces defects and the optical apparatus can well meet the performance requirements for inspecting adjacent surfaces defect of TEC components. The inspection resolution can reach 110 lp/mm when equal-optical-path confocal imaging is met, but the inspection resolution reduces to below 45 lp/mm when the defocus is around ±0.20mm. It was noted that the developed technique has obvious advantages of rather good imaging quality, easy adjustment of imaging system, simplified and reliable optical configurations, and improved defect inspection performance.